Introductory notes:A challenging species to age and sex. Sex can be determined only by brood patch / cloacal protuberance during the breeding season. Some HY/SY individuals can be recognized by their retained juvenile feathers, but since the preformative molt may be complete, individuals lacking juvenile feathers cannot be reliably aged.

QUICK TIPS:

1) Look
at the tail - uniformly narrow and pointed
rectrices OR a mix of narrow and broad rectrices are
indicative of HY/SY, while uniformly broad and more
rounded rectrices are NOT useful as they are
common among both age classes

2) Check the
outer primary coverts - they are relatively
narrow and pointed with minimal gray edging on HY/SY
birds, and relatively broad and rounded with
reddish-brown edging on AHY/ASY birds

3) Look
at the iris in good light - it is
grayish-brown in HY birds and chestnut-brown
in AHY birds (criterion reliable only in fall)

4) Look
at the inner secondaries - on HY/SY birds up
to 6 inner secondaries have been replaced and
contrast with the more faded and abraded outer
secondaries and primaries, while on AHY/ASY birds all
secondaries and primaries are of uniform age and wear

Note that some HY Song Sparrows appear to undergo a complete preformative molt, therefore birds in spring that have fully adult plumage should conservatively be aged as AHY rather than ASY. Some intermediates may also be difficult to age in spring.

JUV - U
Lack of a distinct facial pattern, wing and tail often
still growing

Ageing and sexing details:

JAN - JUL: after-hatch-year (after-second-year)
unknown

Body plumage does not provide any clues to
age or sex in Song Sparrows. Sex can be determined only during the
breeding season by brood patch or cloacal protuberance. The
condition of the wing and tail can be assessed to determine age,
although by spring the feathers have become worn enough that is often
difficult to be certain, and many individuals are better called AHY.

Photo by Marcel Gahbauer,
McGill Bird Observatory (QC), April 2006

Primary
coverts are somewhat broader and more rounded than on SY birds, but the
distinction is slight. AHY/ASY birds also tend to have somewhat more
pale brown edging along the primary coverts, but again this can be
difficult to judge. Considering this and the potential for some HY birds to undergo a complete preformative molt, most should be called AHY unless they are have clear SY characteristics.

Photo by Marcel Gahbauer,
McGill Bird Observatory (QC), April 2006

Photo by Peter Pyle, Merry Lea (IN), May 2005

Photo by Peter Pyle, Merry Lea (IN), May 2007

AHY/ASY birds generally have broader rectrices than SY birds, as shown in
the second photo below. However,
by spring the tips can be quite abraded, and the feathers often look
quite tapered, as for SY birds, and thus tail shape should be used with
caution for ageing, and in combination with the wing. Note too
that the presence of growth bars across the tail is NOT useful, as the
photo of a known ASY bird below illustrates.

Body plumage does not provide any clues to
age or sex in Song Sparrows. Sex can be determined only during the
breeding season by brood patch or cloacal protuberance, while the
condition of the wing and tail can be assessed to determine age,
although by spring the feathers have become worn enough that is often
difficult to be certain, and many individuals are better called AHY.

Photo by Peter Pyle, Southeast Arizona, June 2005

Primary coverts are somewhat narrower and more tapered than on ASY
birds, but the distinction is slight. SY birds also tend to have
somewhat less edging along the primary coverts, but again this can be
difficult to judge, and as a result many birds in spring should be aged
AHY, unless they are particularly distinct.

SY sparrows have relatively narrow and
tapered rectrices that tend to become abraded rather quickly.
However, as ASY tails can also be quite worn by spring, tail shape
should be used with caution, and only in combination with wing molt to
determine age. The tail is most useful for ageing in cases where there is a molt limit among the rectrices as in the example below (worn outer four juvenile rectrices contrasting with the fresher replaced central rectrices).

Body plumage does not provide any clues to
age or sex in Song Sparrows. Sex can be determined only during the
breeding season by brood patch or cloacal protuberance, while the
condition of the wing and tail can be assessed to determine age.

In mid-late summer, it is occasionally
possible to age some Song Sparrows as SY. As all AHY birds will be
molting extensively at this time, the key is to look for retained
juvenile feathers, which are very pale and contrast sharply with
adjacent replaced feathers. The greater alula and outer primary
coverts are likely to be particularly faded and abraded.

Photo by Marcel Gahbauer,
McGill Bird Observatory (QC), August 2005

The photo below illustrates a wing in mid-moult, with
three secondaries in the process of growing in, and all the inner ones
still unreplaced. Note the very pale old outer primary covert and
greater alula, as well as the unreplaced and worn outermost primary.

Photo by Marcel Gahbauer,
McGill Bird Observatory (QC), August 2005

The tail is not helpful
in diagnosing individuals as SY if it has already been replaced, as in the photo below. If instead the bird is seen just before replacing the tail, as in the second photo below, the extreme wear can be evident if juvenile rectrices have been retained to this point.

Body plumage does not provide any reliable clues to
age or sex in Song Sparrows, though sometimes HY birds have a somewhat
more buffy tinge to their underparts.

Photo by Marcel Gahbauer,
McGill Bird Observatory (QC), August 2005

Photo by Marie-Anne
Hudson, McGill Bird Observatory (QC), August 2007

Primary coverts are somewhat narrower and more
tapered than on ASY birds, but the distinction is slight. SY birds
also tend to have somewhat less edging along the primary coverts, and
when present, it is more beige than rusty brown.

Photo by Marie-Anne
Hudson, McGill Bird Observatory (QC), August 2007

Photo by James Junda, McGill Bird Observatory (QC), September 2008

HY sparrows have
relatively narrow and tapered rectrices that tend to become abraded
rather quickly.

Juvenile Song Sparrows have sparse streaking
on the upper breast, lacking the central breast spot of adults.
The crown is also much less distinctly marked than older birds, and the
remnants of the juvenile gape are often still visible at the base of the
bill.

Photo by Gay Gruner,
McGill Bird Observatory (QC), June 2009

Photo by Marcel Gahbauer,
McGill Bird Observatory (QC), August 2005

The wing is generally dull brown, with the primary
coverts having minimal pale edging.

Photo by Gay Gruner,
McGill Bird Observatory (QC), June 2009

Photo by Marcel Gahbauer,
McGill Bird Observatory (QC), August 2005

The photo below shows a
very young Song Sparrow in the process of growing its tail; once
completed it is similar to the HY tail shown above.